Liquid switch



Aug. 6, 1935. w E 2,010,398

LIQUID SWITCH Filed April 5, 1934 INVENTOR 415ml /f[[/V TITOR PatentedAug. 6, 1935 UNITED STATES PATENT OFFICE LIQUID SWITCH Alexis W. Keen,Passalc, N. 1.,

assignor, by memo Application April 5, 1934, Serial No. 719,101

1 Claim.

My invention relates to liquid switches, and more particularly to adelayed action mercury switch. For many purposes it is desired to use aliquid switch for making and breaking electrical circuits carrying smallcurrents. Such switches are mainly used for making and. breakingelectrical circuits controlling the actuation of other circuits.

Such switches usually comprise a casing of electrical insulatingmaterial such as glass either with or without a base of insulatingmaterial such as a phenolic condensation product, hard rubber, or thelike, for inserting electrodes. A liquid, usually mercury, is disposedwithin the container so as to make and break contact between theelectrodes in response to movement of the container. The switch ispivotally mounted so that it may be readily tilted in response tophysical movements or electrical impulses so as to initiate or breakcircuits for actuating other apparatus.

I provide a switch of this general class in which a. circuit iscompleted for a period of time when the switch is moved from oneposition to another. When the switch is returned to its originalposition, it is re-set without completing a circuit.

I accomplish the foregoing result by providing a barrier of insulatingmaterial intermediate the casing, which barrier is provided in a lowerportion with a passageway for the movement of the conducting liquid. Oneelectrode is disposed near the bottom of the switch so as to readilyengage a pool of the liquid. Another electrode is disposed on the sameside of the carrier but well above the first mentioned electrode so thatwhen a pool of the liquid is formed immediately behind the barrier bothelectrodes are immersed to complete a circuit. The circuit persists fora period of time depending upon the time required for the liquid toescape through the passageway in the barrier. When the switch isrestored to its initial position the liquid returns through thepassageway but does not complete a circuit between the electrodes.

The accompanying drawing illustrates a present preferred embodiment ofmy invention, in which Fig. l is a side elevational view of the switchin its set position;

Fig. 2 is a similar view showing theswitch in its circuit completingposition;

Fig. 3 is a similar view of the switch after the circuit is interrupted;and

Fig. 4 is a similar view the resetting operation.

Referring to the drawing, a liquid switch I of the switch duringcomprises a container 2 of insulating material. If desired the container2 may be of glass so that the operation of the switch is visible. A

base 3 of moldable insulating material such as hard rubber, or the like,is placed over one end of the container and supports electrodes 4 and 5which extend through the wall of the container in a manner well known tothe art. It is to be understood that in practice the switch I is mountedin suitable mechanism, not shown, for giving it a rocking movement. Suchmechanism is well known in the art and may be operated directly byphysical movement of other apparatus or electro-magnetically byelectrical impulses from other sources.

Intermediate the length of the container 2, and preferably substantiallycentrally thereof, there .is disposed a barrier 6 of insulatingmaterial,

soapstone being suitable for the purpose. In the lower portion of thebarrier a passageway l is formed. In the drawing the passageway l is atthe lower surface of the barrier. A passageway 8 is also provided at theupper surface for the movement of gases in case the container is filledwith an inert gas.

The electrode 4 extends through the base toward the barrier and isshaped normally to lie in a pool of the conducting liquid 9, usuallymercury.. The electrode 5 also projects toward the barrier but is spacedwell above the electrode 4 so that when the switch is in its setposition, illustrated in Fig. 1, an electrical contact is not madebetween the electrodes 4 and 5. The electrode 5 may be connected to thebarrier 6 for support. The base of the electrode 5 is preferably coveredwith insulation I 0 to prevent the completion of a circuit when theswitch is in the "set position if a considerable quantity of liquid 9 isused. Upon tilting the switch to the position shown in Fig. 2, theconducting liquid 9 forms a pool directly behind the barrier E tocomplete the circuit. The circuit so completed persists for a period oftime depending upon the movement of the liquid 9 through the passagewayI. It is to be understood that the size of the passageway and the amountof liquid present may be varied to give the desired time delay action inmaintaining the circuit.

After the liquid has flowed through the passageway l the circuit isinterrupted as shown in Fig. 3. Thereafter the switch may be reset bytilting it to the position shown in Fig. 4, at which time the conductingliquid returns through the passageway l but without completing a circuitbetween the electrodes 4 and 5.

While I have shown and described a present preferred embodiment of myinvention, it is to be understood that it may be otherwise embodiedwithin the spirit of the invention and the scope of the appended claim.

Having thus described my invention. what I claim and desire to protectby Letters Patent is:

In a. liquid switch, a container of insulating material, a barrierdisposed substantially centrally of the container, said barrier having apassageway in a lower portion thereof to permit the movement of aconducting liquid, an electrode disposed near the bottom of thecontainer; and

a second electrode disposed on the same side 01' the barrier as thefirst-named electrode but thereabove and mechanically connected to thebarrier to serve as an anchor therefor whereby when the switch is tiltedto impound the liquid direction the liquid returns through the passage-10 way without completing a circuit.

ALEXIS W. KEEN.

